Network connection problem

I'm trying to connect two machines together. I know that I can't just connect immediately without doing some testing beforehand, like for NAT. I got this script from the Unity documentation. I think it's supposed to determine if NAT should be used or not, but some parts look a little messed up to me:

1) The line that says "case ConnectionTesterStatus.NATpuchthroughAddressRestrictedCone:" doesn't execute any code. 2) There are 2 case's that say "ConnectionTesterStatus.LimitedNATPunchthroughPortRestricted:"

As of right now I am unable to establish a connection with this script. Are there any network experts that can fix this script up for me so I can actually make a simple connection?

var testStatus = "Testing network connection capabilities.";
var testMessage = "Test in progress";
var shouldEnableNatMessage : String = "";
var doneTesting = false;
var probingPublicIP = false;
var serverPort = 9999;
var connectionTestResult = ConnectionTesterStatus.Undetermined;

// Indicates if the useNat parameter be enabled when starting a server
var useNat = false;

function OnGUI() {
    GUILayout.Label("Current Status: " + testStatus);
    GUILayout.Label("Test result : " + testMessage);
    GUILayout.Label(shouldEnableNatMessage);
    if (!doneTesting)
        TestConnection();
}

function TestConnection() {
    // Start/Poll the connection test, report the results in a label and 
    // react to the results accordingly
    connectionTestResult = Network.TestConnection();
    switch (connectionTestResult) {
        case ConnectionTesterStatus.Error: 
            testMessage = "Problem determining NAT capabilities";
            doneTesting = true;
            break;

        case ConnectionTesterStatus.Undetermined: 
            testMessage = "Undetermined NAT capabilities";
            doneTesting = false;
            break;

        case ConnectionTesterStatus.PublicIPIsConnectable:
            testMessage = "Directly connectable public IP address.";
            useNat = false;
            doneTesting = true;
            break;

        // This case is a bit special as we now need to check if we can 
        // circumvent the blocking by using NAT punchthrough
        case ConnectionTesterStatus.PublicIPPortBlocked:
            testMessage = "Non-connectble public IP address (port " + 
                serverPort +" blocked), running a server is impossible.";
            useNat = false;
            // If no NAT punchthrough test has been performed on this public 
            // IP, force a test
            if (!probingPublicIP) {
                connectionTestResult = Network.TestConnectionNAT();
                probingPublicIP = true;
                testStatus = "Testing if blocked public IP can be circumvented";
                timer = Time.time + 10;
            }
            // NAT punchthrough test was performed but we still get blocked
            else if (Time.time > timer) {
                probingPublicIP = false;         // reset
                useNat = true;
                doneTesting = true;
            }
            break;
        case ConnectionTesterStatus.PublicIPNoServerStarted:
            testMessage = "Public IP address but server not initialized, "+
                "it must be started to check server accessibility. Restart "+
                "connection test when ready.";
            break;

        case ConnectionTesterStatus.LimitedNATPunchthroughPortRestricted:
            testMessage = "Limited NAT punchthrough capabilities. Cannot "+
                "connect to all types of NAT servers.";
            useNat = true;
            doneTesting = true;
            break;

        case ConnectionTesterStatus.LimitedNATPunchthroughPortRestricted:
            testMessage = "Limited NAT punchthrough capabilities. Cannot "+
                "connect to all types of NAT servers. Running a server "+
                "is ill advised as not everyone can connect.";
            useNat = true;
            doneTesting = true;
            break;

        case ConnectionTesterStatus.LimitedNATPunchthroughSymmetric:
            testMessage = "Limited NAT punchthrough capabilities. Cannot "+
                "connect to all types of NAT servers. Running a server "+
                "is ill advised as not everyone can connect.";
            useNat = true;
            doneTesting = true;
            break;

        case ConnectionTesterStatus.NATpunchthroughAddressRestrictedCone:
        case ConnectionTesterStatus.NATpunchthroughFullCone:
            testMessage = "NAT punchthrough capable. Can connect to all "+
                "servers and receive connections from all clients. Enabling "+
                "NAT punchthrough functionality.";
            useNat = true;
            doneTesting = true;
            break;

        default: 
            testMessage = "Error in test routine, got " + connectionTestResult;
    }
    if (doneTesting) {
        if (useNat)
            shouldEnableNatMessage = "When starting a server the NAT "+
                "punchthrough feature should be enabled (useNat parameter)";
        else
            shouldEnableNatMessage = "NAT punchthrough not needed";
        testStatus = "Done testing";
    }
}

To answer your first question about the "case ConnectionTesterStatus.NATpunchthroughAddressRestrictedCone:" line... it actually is running code. Its running the code below it. So in the case of the case statement there is no break statement to get out so it keeps on going through the next case statement. So, it is doing the ConnectionTesterStatus.NATpunchthroughFullCone code.

As for the second question, I think its the case of copy/paste error. Both sets of code are pretty much doing the same thing.

This script is only testing network capability. There is no code setting up a server and no code connecting to a server. Is there more code to look at?